Shellfish: Types, Characteristics, and Market Forms PDF

LESSON X **SHELLFISH** Fish and shellfish are very perishable and deteriorate rapidly after removal from water. Fish with shells as distinguish from fish with bones forms two groups based on differences in the character of the shells. Oysters, clams, scallops live in hinged shells. They have unseg...

LESSON X **SHELLFISH** Fish and shellfish are very perishable and deteriorate rapidly after removal from water. Fish with shells as distinguish from fish with bones forms two groups based on differences in the character of the shells. Oysters, clams, scallops live in hinged shells. They have unsegmented bodies and the whole portion is eaten except in the case of the scallops which only the muscles are used. Lobsters, crabs, and shrimps have various appendages and shell-like crusts that conform to the shape of their bodies. Fifteen percent of the total fish consumption in the Philippines consist of shellfish. It also includes squid, cuttlefish and sea cucumber. The production of fish in saltwater bodies such as in coves and shores is called ***mariculture***. Mariculture is presently applied to tahong and oysters and is relatively in its infancy in the Philippines. **Types of Shellfish: Crustaceans and Mollusks** ***Crustaceans-*** are shellfish with hard shells over the back along the claws but have softer shells covering and the lower part of the body and legs. Examples of these are crabs, lobsters and shrimps. ***Crabs-***there are various types of crabs commonly found in the Philippines: the alimango or green crab, the alimasag or blue crab and the talangka. The talanka or kapi is unique due to its small size , about one-fourth of the size of the regular crab. A fresh water crab obtained from the rivers has a shell that covers the lower part of its body and is soft enough to be edible. The carapace or hard shell covers its back which contains the fat or aligi that may be separated from the meat and preserved , called taba ng talangka. It is eaten as sauce. A delicacy prepared laboriously by experts. The bigger crabs, alimango amd alimasag, also contain aligi which in normally with its meat. ***Lobster-*** is popular shellfish in New England Fisheries. The claw meat is preferred and brings a higher price than the tail meat. Lobster are expensive and marketed mainly for exports. ***Shrimps-*** are more commonly eaten than lobster. Like crabs, some shrimps are also small and would normally be eaten whole with their shells. *Suahe* is a saltwater shrimp while *Ulang* and *Taganton* are freshwater shrimps. **Mollusks-** have soft unsegmented bodies and are protected by calcareous shells in one or more pieces or enclosed in hard shells which are largely mineral in composition. Examples of these are oysters, clams, scallops and sea muscles. There are two types of mollusk: the univalves , with only one shell and the bivalves, with two shells. The mollusks are usually hard all over so that they are not in any case edible. Examples of univalves is *Kuhol* while example of bivalves are *clams, (halaan), kabibi, tulya, oysters (talaba) and mussels (tahong).* The composition of the edible portion of mollusk is quite different from fin fish and crustaceans, even if the former's shell are not normally eaten. Their flesh are generally leatherly in texture. They are comparatively high in glycogen content. For instance, in the case of oysters, the ph does not rise after death but decreases down to as low as 4.8 due to the formation of lactic acid from glycogen. The ph serve as an index of freshness of oysters. ***Tahong-*** is a salt water mussel cultured mostly in Bacoor, Cavite. Its meat is considered more delicious than oyster. ***Oyster-*** grown in artificial beds are usually of better quality than those grown in natural beds. Oyster eggs are now being planted in many waters. When the egg are hatched, the tiny oysters, which are not any larger than the point of a needle, move about the water and finally attached themselves to somebody such as stone, stick or shell. They grow slowly and at the age of one year they have usually reached about the size of a silver quarter. Oysters are harvested by picking and scooping the shells from tge button of the sea. ***Clams-*** are of two types: the hard shell-clam and the soft shell clams. The former have tightly shut shells but the latter may partially open shells because of the long siphon extending from the interior. Clams are dug by hand. ***Scallops-*** are highly price because of their buttery texture and delicate flavor. Scallops have two shells and capable of swimming freely through water. **Market Forms of Shellfish** Shellfish are sold in the shell , shucked or removed from the shell or cooked. All forms are quickly perishable and care is needed in selecting them. **Live Shellfish** Ideally, crabs, clams, mussels, snails, oysters and shrimps should be marketed alive. A live crab is indicated to be fat if it claws do not have sharp teeth and if it is heavy in weight. The female crab has rounded apron and usually contain aligi; the male crab has a narrow and more pointed apron. Filipino consumers generally prefer the female variety. Because of the proximity of most markets to the sources of shellfish, live species can be sold to consumers. **Whole Shellfish** Whole shellfish are served in the form in which they are caught but are no longer alive. The head and thorax are intact. Filipinos are fond of eating the heads and extremities of crabs and shrimps. **Shucked Shellfish** Oysters, clams, mollusk and scallops when removed from the shell are known as shucked shellfish. Fresh shucked shellfish have a translucent but become opaque when no longer fresh. **Headless Shellfish** Shrimps, lobsters and prawns are marketed for export in headlines form; the head and thorax removed. Foreign consumers do not favor the consumption of these parts of the shellfish. Furthermore, the head is removed mainly because it is the main source of bacterial spoilage. **Cooked Form** Most cooked shellfish are canned for export. The meat of shrimps, crabs, and lobsters are usually popular items for canned products. At present, only a small volume of canned and cooked shellfish is available locally; most of it is imported.